Hot gas engine heater heads

ABSTRACT

Four pairs of manifolds of the heater head have four corresponding pipes disposed in 90* segments of a circle with the ends bent more than 90* to connect with the manifolds. This configuration provides improved engine efficiency by uniform heating and shielding of the manifolds from the most intensive radiation and convection by parts of the pipes disposed between the manifolds and the center of the heater head.

United States Patent 1191 a v v Grahn July 9, 1974 [54] HOT GAS ENGINEHEA I ER HEADS 3,333,225; 1/1323 3525:1511. /525 ,l5 121 5 b r 165125Inventor Per Goran Grab", Malmo Sweden 3,412,787 11/1968 M i llig zfan165/175 [73 Assigneez Kommanditbolaget United Stirling 3,662,817 5/1972Kendrick et a1. 165/175 (Sweden) AB & Co., Malmo, S d PrimaryExaminer-Edgar W. Geoghegan Assistant Examiner-H. Burks,Sr. [22] Flled:19-73 Attorney, Agent, or Firm--Laurence R. Brown [21] Appl. No.:388,563

' [57]- I ABSTRACT [30] Foreign Application Priority Data 1 Four pairsof manifolds of the heater head have four Aug 22 1972 Great Britain U3897"72 corresponding pipes disposed in segments of a circle with theends bent more than 90 to connect with [52] U S 60/517 /125 165/175 themanifolds. This configuration provides improved [51] V i 7/06 F25b g/OOengine efficiency by uniform heating and shielding of [58] Fieid "60/5175 524 the manifolds from the most intensive radiation and 5 convectionby parts of the pipes disposed between the manifolds and the center ofthe heater head. [56] References Cited 2 tilains, Drawing Fignres UNITEDSTATES PATENTS A i m M 4 H m "w m 2,817,950 12/1957 Van Weenan et al60/525 2,828,601 4/1953 Meyer 1 HOT GAS ENGINE HEATER HEADS Thisinvention relates to a hot gas engine heater head of the kind comprisingat least one pair of parallel manifolds connected to at least onecylinder top and one top of a regenerator-cooler unit, the two manifoldsin each said pair of manifolds being interconnected by substantiallyparallel pipes extending in planes perpendicular to the axes of themanifolds.

During the running of a hot gas engine the heater head'is exposed toradiation of heat from a burner and to contact with a flow of hotcombustion gases. The heater head is cooled internally by a flow ofworking gas. In order to obtain a high efficiency of the engine thepressure and the temperature of the working gas should be very high thelimit being determined by the material used in the heater head.Therefore it is desirable that the parts of the heater head exposed tothe highest temperatures regarding radiation and convection should beuniformly heated and uniformly internally cooled and they should alsoform a substantial part of said heater head. With these requirements inmind the invention is intended to provide an improved heater head of thekind referred to.

According to the present invention a heater head of the kind referred tois characterised in that said pipes are formed as segments of circlesalong the greater parts of their lengths and that adjacent to their endsthey are bent through more than'90 prior to their connections to saidmanifolds.

In a preferred construction the heater head comprises four pairs ofmanifolds and the said segments are of substantially equal length eachextending through approximately 90 of a circle.

How the invention may be put into practice is described in more detailwith reference to-the accompa nying drawing in which:

FIG. 1 is a side view of a heater head according to the invention, and

FIG. 2 shows the heater head of F IG. I viewed from above.

The drawing shows four manifolds l, 2, 3 and 4 extending from thehigh-temperature cylinder ends (not shown) of a four cylinder hot gasengine. Four manifolds 5, 6, 7 and 8 are connected at their lower endsto regenerators (not shown) of the same engine. The manifolds form fourpairs, i.e. 1-5, 26, 3-7 and 4-8. In each pair the two manifolds areinterconnected by a plurality of horizontally-extending pipes 9 ofsubstantially equal length and shape. The said pipes are formed assegments of circles along the greater parts of their lengths andadjacent to their ends they comprise end portions 10 which are bentthrough more than prior to their connections to the manifolds.

During operation of the engine heat is supplied by a burner (not shown)disposed centrally relative to the pipes 9. Heat is transmitted to thepipes by radiation and convection. It will be understood that accordingto the invention the manifolds 5-8 are shielded from the most intensiveradiation and convection by the parts of the pipes 9 located between themanifolds and the center of the heater head.

What is claimed is:

1. A hot gas engine heater head of the kind comprising at least one pairof parallel manifolds connected to at least one cylinder top and one topof a regeneratorcooler unit, the two manifolds in each said pair ofmanifolds being interconnected by substantially parallel pipes extendingin planes perpendicular to the axis of the manifolds, characterised inthat said pipes are formed as segments of circles along the greaterparts of their lengths and that adjacent to their ends they are saidsegments are of substantially equal length each extending throughapproximately 90 of a circle.

1. A hot gas engine heater head of the kind comprising at least one pairof parallel manifolds connected to at least one cylinder top and one topof a regenerator-cooler unit, the two manifolds in each said pair ofmanifolds being interconnected by substantially parallel pipes extendingin planes perpendicular to the axis of the manifolds, characterised inthat said pipes are formed as segments of circles along the greaterparts of their lengths and that adjacent to their ends they are bentthrough more than 90* prior to their connections to said manifolds.
 2. Aheater head according to claim 1, characterised in that it comprisesfour pairs of manifolds and that the said segments are of substantiallyequal length each extending through approximately 90* of a circle.